Programmable TRVs

[GMM]

Hmm...best not to get started on the door shutting issue!

I'm now thinking that I do kind of need to do the whole lot to make it worthwhile as my wife works from home. Although my initial thoughts were to turn off rooms like the living room and dining room during the morning heating cycle, it would be better if I could turn most of the house down to allow her to use the CH during the day. Since our gas bills without that are north of a grand a quarter, I'd hate to think what they would be with the whole house banging away all day.

Thinking of your plan, I can see it could make sense to shift the thermostat, or add another, to make it work better. That will take a little bit of thinking about as I'm hoping to avoid heating a lot more than 1/3 of the house during the day - more like 90%

Of course, the efficiency issue would be raised by this and we'd still be heating the hallway to no real purpose but at least the electric heater she uses at the moment wouldn't be running all day and there would be a comfort gain. Assuming she could learn the concept of closing the door, that is......

[Andrew Gabriel]

For the room I work in (corner of the main living room), I have installed an air-sourced heat pump. I originally did this for cooling in the summer, but actually, it gets very much more use as a heater, pumping in heat from outside in winter.

It's not good when outside temp is 0-4C as it ices up and has to run defrost cycles which probably makes it no better than just running an electric heater, but above and below that range, it works very well as a heater.

[GMM]

I've always thought they were a good way to go but I'm not sure installation would be simple in a Victorian house. In the future, there will be some significant works around here that will include creating a proper office. That will be the time to consider more radical alternatives but, for now, modifying CH controls seems the simplest way forward.

[Kostas Kavoussanakis]

I have the discontinued Honeywell CM system, with 2 room units, each with 2 zones, driving 8 radiators.

Programming is pretty much fire and forget, batteries are no issue and it has solved my original problem: heating for a comfort a 22m2 lounge with no upstairs (insulated loft), 8m2 windows on three sides, sitting lower than the rest of the house, at the times when the rest of the house does not need heated. I don't know if it has made a difference in the bills; in reference to Andrews post re new/old design, I have (had? sniff, sniff...) a Potterton Netaheat that cycles on and off rather than modulate. From memory (so details may need checked), you can easily program it with a target temperature for a specific period and it starts when it decides (taking past performance and current temp into account, I believe) so as to be at that temperature at the requested time (rather that setting the time you want it to start chasing the target). It can also detect open windows and block the rad, but I have not tried either of these.

I don't know if Honeywell do something similar anymore, but if you can get it discontinued or used on ebay, it may be worth a shot. You can set it up on the first few rads that you need, leave the rest with standard TRVs and build it up as needs and funds allow.

I hope this helps,

Kostas p.s.: Thanks about the discussion re running as many as one can in parallel, Andrew, I may re-tune my set-up to that effect.